Traditionally, homes have been built using bricks for more than 1000 years. We have lots of clay and the red color comes naturally.
Wall thickness is 430mm (17 inches), just barely enough to cover the 2015 building regulations.
Building regulations state that a 150 sqm (1600 sqf) building can use 36,7 kWh/sqm/year to heat up the house.
This requires 300mm (12 inches) of classic insulation. And since a standard brick is 120mm (5 inches) thick, the wall should have been 520mm (21 inches) thick.
In this home I use a new energy efficient brick that is only half as thick, and I replace some of the standard insulation with modern PUR foam insulation, which brings my wall thickness to 430mm (17 inches).